Pregnancy-associated weight gain and failure to lose weight after birth contributes to the development of overweight and obesity in Hispanic women, who have prevalence rates exceeding 70%. Recent evidence shows that obesity is associated with systemic and fat tissue inflammation which can facilitate the development of obesity-related chronic diseases and contributes to the development of postpartum depression. Despite the well-established beneficial effects of exercise on weight, women tend to underparticipate in physical activity during the childbearing years. Further, the mechanisms underpinning the interplay of overweight, obesity, physical activity, and subsequent risk such as inflammatory processes or postpartum depression are not clear. The proposed study seeks to test a social support intervention, "Madres para la Salud" [Mothers for Health], to explore the effectiveness of a culturally specific program using "bouts" of physical activity to effect changes in body fat, fat tissue inflammation, and postpartum depression symptoms in sedentary Hispanic women. This innovative program has the potential to advance our understanding of the relationship between moderate increases in physical activity and specific health outcomes. The study aims are to:1) Examine the effectiveness of the Madres para la Salud for reducing the distal outcomes in: (a) body fat (b) systemic and fat tissue inflammation and (c) PPD symptoms among postpartum Hispanic women compared with an attention control group, at 6 and 12 months, after controlling for dietary intake;2) Test whether the theoretical mediators, intermediate outcomes, of social support and walking, and environmental factor moderators, affect changes in body fat;systemic and fat tissue inflammation;and PPD symptoms among postpartum Hispanic women at 6 and 12 months, and 3) Determine the relationship between the immediate outcome of walking (minutes walked per week) and change in the distal outcomes of: (a) body fat (b) systemic and fat tissue inflammation and (c) PPD symptoms. A prospective, randomized controlled trial will guide the study. A sample of 140 sedentary Hispanic women, 18-35 years, and between 6 weeks and 6 months following childbirth will be used. Participants will be randomly assigned to the intervention or attention-control group. The intervention group will have weekly walking sessions and support interventions with Promotoras. The attention-control group will receive health newsletters and follow-up phone calls. Data will be gathered at baseline, 3, 6, 9, and 12 months using questionnaires, fat tissue biopsies, blood samples, and a subset sample for DEXA body scans, as well as objective and self-report measures of walking adherence. The intervention's effectiveness will be evaluated using a mixed models analysis of variance (ANOVA) comparing the two groups, structural equation modeling (SEM), and evaluating the relationship between walking and body-fat loss. The results will have significance for women's health providers who seek to improve the long-term health of Hispanic women. PUBLIC HEALTH RELEVANCE: The proposed project tests an intervention that can be integrated into the daily lives of Hispanic women following childbirth. The intervention will use culturally sensitive strategies and planned supports during walking activities to decrease body fat and postpartum depression symptoms, while improving the cellular processes related to excess body fat.